The muscle community at the University of Pennsylvania has established an outstanding training program in Muscle Biology and Muscle Disease, supported in part by the T32 mechanism. Members of the Penn community are known world-wide for excellence in muscle research, and this program facilitates collaborative training opportunities for predoctoral students and postdoctoral fellows. Our training program enables trainees to work in laboratories directed by principal investigators who are leaders in the study of the cell biology, developmental biology, physiology, and/or pathology of muscle. Although the range of interests and expertise of the trainers on this grant is broad, the training is focused on elucidating the mechanisms of muscle function and disease. The program is designed to take advantage of the highly collaborative nature of the faculty, thus providing the trainees with the opportunity to integrate molecular and physiological aspects of muscle biology into their research. This training diversity provides an unparalleled training environment in the area of muscle biology. This is evidenced by the many prominent scientists around the world who have trained in this field at the University of Pennsylvania.